Infiltration in reclaimed mined land ameliorated with deep tillage treatments

Reclamation of mined land with heavy machinery can result in soil compaction. Compaction increases soil bulk density and reduces porosity, water infiltrability, root elongation and crop productivity. Mine operators have used deep tillage equipment to alleviate the compaction problem. The main objectives of this study were to examine (1) the effect on infiltration in reclaimed surface mined land of a deep tillage treatment, and (2) the subsequent changes in infiltration after the amelioration. The experiment was conducted at the Horse Creek Mine near Conant, Perry County, IL, USA. The soil was classified as Schuline series, which is a fine, loamy, mixed, mesic, Typic Udorthents. The treatments included tillage depths of 20 (as a control), 40, 60 and 80 cm. Infiltrometers and runoff plots were installed to evaluate infiltration and rainfall-runoff relationships affected by the treatments. Results indicated that the steady infiltration rates of the 40- and 60-cm tillage treatments were lower than that of the control treatment successively during the experimental period for 3 years. Results also revealed that the 80-cm tillage treatment increased infiltration and reduced surface runoff most. Even though the beneficial effects declined over a 3-year test period, the 80-cm tillage is recommended in the amelioration of soil compaction because tillage depths less than 80 cm did not enhance water infiltration rate much.